1. Field of the Invention
This invention relates generally to magnetic field antennas, and more particularly to a magnetic field antenna particularly suitable for use in a device for deactivating or interrogating electronic article surveillance tags. Electronic article surveillance tags are produced in a variety of configurations and employ various operating principles, but all contain a device whose presence can be detected by detection circuitry located at an exit from the protected area. Some types of electronic article surveillance tags cannot be deactivated and must be removed from the article being protected at the point of sale, but others may be deactivated through the application of an intense magnetic radiation field designed to open circuit, for example, by burning out a fusible link, short out, for example, by melting a portion of the tag, or otherwise disable the tag. The antenna according to the invention is particularly suitable in a deactivating station for deactivating such tags, and may also be used at protected exits to interrogate and detect the presence of tags.
2. Prior Art
Various antennas particularly useful for deactivating EAS tags have been proposed, but most have various drawbacks such as excessive bulk, excessive cost or excessive radiation outside of the deactivation station.